This invention relates to the field of information processing and more particularly to systems for implementing off-line digital management rights.
Increased use of electronic computer networks, such as the Internet has resulted in a fundamental problem now facing content providers, namely, the problem of how to prevent the unauthorized use and distribution of digital content. These content providers include publishers of video games, music, books, medical information, information database providers, and providers of interactive web players. Examples of interactive web players currently available on the market are Quicktime 4™ available from Apple Computer, Inc.®, RealPlayer™ available from RealNetworks, Inc.® and Shockwave 7™ available from MacroMedia, Inc.®.
These content providers are concerned with getting compensated for their work. Unauthorized copying and use of content providers works deprives rightful owners of billions of dollars according to a well-known source. Unauthorized copying is exercebated because consumers can easily retrieve content, and technology is available for perfectly reproducing content.
A number of mechanisms have been developed to protect against unauthorized access and duplication and to provide digital rights management. One method is a digital rights management system that allows a set of rules to determine how the content is used. Another method (for software) for curbing unauthorized duplication is the use of a scheme which provides software tryouts or demos that typically work and expire after a specific duration. Other methods use a copy protection scheme that limits the number of copies that a user can make, after which additional copying results in corrupt copies. Further, an alternate scheme requires the presence of a license on a client workstation for the software to operate.
Many of the aforementioned schemes are typically implemented using “encryption/decryption” of the digital content. Encryption is the conversion of data into an unintelligible form, e.g., ciphertext, that cannot be easily understood by unauthorized users. Decryption is the process of converting encrypted content back into its original form such that the it becomes intelligible. Simple ciphers include the rotation of letters in the alphabet, the substitution of letters for numbers, and the “scrambling” of voice signals by inverting the sideband frequencies. More complex ciphers work according to sophisticated computer algorithms that rearrange the data bits in digital information content.
In order to easily recover the encrypted information content, the correct decryption key is required. The key is an algorithm that decodes the work of the encryption algorithm. The more complex the encryption algorithm, the more difficult it becomes to decode the communications without access to the key. Generally, there are two types of key schemes for encryption/decryption systems, namely (1) Public Key Systems (PKS) or asymmetric systems which utilize two different keys, one for encryption, or signing, and one for decryption, or verifying; and (2) nonpublic key systems that are known as symmetric, or secret key, systems.
Although the use of public or private key can be an effective way to prevent access to digital content, the transfer of keys often requires extensive coordination with the end user. Also, the use of keys in the related art does not always provide flexible licensing arrangements, or an efficient way to handle many instances of different deliverable digital content products.
Therefore, there is a need to resolve the aforementioned problem relating to conventional approaches for protecting digital information particularly with regard to managing the digital rights for off-line distribution of interactive web content and music.